1. Field of the Invention
The present invention relates to a military radar communication system or a radio communication system of the type in which mobile transmitter-receiver apparatus is provided in which a plurality of operating frequencies is constantly changed in accordance with a frequency hopping technique.
2. Description of the Prior Art
Systems in which operation is carried out in accordance with a frequency hopping principle are known, for example, from U.S. Pat. No. 3,426,279. In such systems, a shift in the operating frequencies in brief time intervals, respectively, is carried out in accordance with a predetermined schedule. This schedule is known to all stations participating in private message exchange and is stored, for example, in an airborne (onboard) computer, e.g. over a greater period of time of approximately one day. Airborne computer systems such as this are generally already provided in cryptologic installations, and do not require a great additional expense for further tasks. These considerations basically also apply to locating (position finding) installations.